Hi nobrot,

Very easy to do - except if your scene is inside a room since IBL is created as a giant sphere that is larger than the Carrara workspace - it won't shine through walls. ;)

Build your scene and then place a spherical camera in the middle of it. It takes a little bit more fussing with the camera elevation to get it perfect so put the resulting render in a new scene as a background element with a reflective sphere in it for proofing. If everything looks ok, then do the HDR work and your set. 

HDR/IBL, when used in a scene, is best for scenes that actually have no props. The whole point is to let the map do the work. Creating a scene that has the same props in it as the HDR map will lead to double reflections.

Mark